Should colours and sizes be variants or separate products in Shopify?

Use variants when colour, size or another option represents the same core product and shoppers should choose between those options on one product page. Use separate products when each version needs substantially different merchandising, content, imagery, pricing logic or search visibility. The goal is to keep the catalogue understandable for shoppers while avoiding unnecessary duplication. For most apparel and footwear stores, size and colour are usually best handled as variants unless the products are genuinely distinct.